Sometimes I am getting this error randomly. I have checked the size of data array, all are same sized. > const json = require('./bt-json'); const plots=[]; json.forEach(jsonI=>{ const points = jsonI.series.points; plots.push({x:points.map(point=>moment(point[0])),y:points.map(point=>point[1]),name:jsonI.series.name}); }) nodePlotLib.plot(plots);